The present invention relates to a heat exchanger.
A heat exchanger used as a condenser for a car air conditioner is known (Japanese Patent Application Laid-Open (kokai) No. H7-35442). The heat exchanger includes a pair of header tanks disposed apart from each other such that their longitudinal direction coincides with a vertical direction; a plurality of heat exchange tubes disposed between the header tanks such that their longitudinal direction coincides with a horizontal direction and they are spaced apart from one another along the longitudinal direction of the header tanks, the heat exchange tubes having opposite end portions connected to the corresponding header tanks; fins disposed between adjacent heat exchange tubes and on the outer sides of the heat exchange tubes at the opposite ends; and side plates which are disposed on the outer sides of the fins at the opposite ends and whose opposite ends are joined to the corresponding header tanks. Each header tank has a tubular tank main body which is open at opposite ends thereof, and closure members press-fitted into the tank main body so as to close the openings of the tank main body at opposite ends thereof. The closure members are located at portions of the circumferential wall of the tank main body of each header tank, which portions are located between the opposite end surfaces of the circumferential wall and the heat exchange tubes at the opposite ends. The opposite end portions of the side plates are inserted into through-holes which are formed in the circumferential walls of the tank main bodies of the two header tanks to be located outward of the closure members as viewed in the longitudinal direction of the tank main bodies. The opposite end portions of the side plates are brazed to the circumferential walls of the tank main bodies. Water drain holes (through-holes) are formed in the circumferential walls of the tank main bodies to be located outward of the closure members as viewed in the longitudinal direction of the tank main bodies.
However, in the case of the heat exchanger disclosed in the publication, since the distance between the outer surface of each closure member and a corresponding drain hole is large, water collecting between the outer surface of each closure member and a corresponding drain hole cannot be drained. Therefore, the heat exchanger is poor in water draining performance and may decrease in corrosion resistance.